Tankless Solar Water Heater

ABSTRACT

A fluid storage unit suitable for a tankless solar heater system. The storage unit has an elongated cylindrical hollow vessel having a sealing ring fit within an open end of the vessel abuting a ridge formed on the vessel and a cover attached to the open end of the vessel and abutting the ring to compress it against the ridge to form a fluid tight seal between the cover and the vessel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application serial number 20101020033.7 filed on Jun. 30, 2010 bearing the title “Modular Solar Thermal Storage Units and Tankless Solar Water Heater” and all disclosures are incorporated by reference herein.

BACKGROUND OF THE DISCLOSURE

The present invention is directed to fluid storage units for use in solar fluid heating systems and in particular in tankless water heaters.

As global petrochemical energy shortage and global warming seriously threaten the economic development and health of people's lives, energy conservation and carbon-footprint reduction have become a significant national policy around the world. Solar energy, known for being clean, readily available and safe, has obvious advantages and has caught the attention of most countries in the world. In the solar energy industry, the development of solar thermal water heaters has become a mature technology. Solar thermal systems have been widely used.

In general, various solar fluid heating systems have been created to collect a portion of the energy of the sun for various purposes by heating a fluid. In many cases, the fluid heated is water. The heated water may then be used directly from the solar collector for consumption, for cleaning persons or objects, or for filling a swimming pool. In other cases, the heated water may be supplied to a residential or commercial potable water distribution system. Hot water from the water distribution system is stored for subsequent distribution to hot water lines throughout a building to outlet devices, such as faucets, or to appliances, such as clothes washers, dishwashers or water or steam based radiators. These are typically of two types—direct heating systems and indirect heating systems.

In still other cases, the fluid is used as a secondary fluid for collecting heat and thereafter transferring the heat to water through a heat transfer device. In some of these installations, a solar collector is part of a closed loop system using a secondary fluid, such as glycol, and the heat is transferred to the potable water using a heat exchanger. These systems are complex and inefficient, for example, in the transfer of heat between the secondary fluid and the potable water. It may therefore be desirable to provide a solar heating system where the solar collector heats the potable water directly so as to reduce the number of components and complexity and increase the overall efficiency of the system.

In a few other cases, the heat content of the fluid is converted to another form of energy or directly used to perform some task.

These systems may consist of one or more solar panels holding one or more transparent fluid holding chambers each connected to a fluid inlet for supplying unheated fluid to the fluid holding chambers and to a fluid outlet for removing heated fluid from the fluid holding chambers. When the solar panels are exposed to the incoming sunlight, the fluid converts photons in the incoming solar rays into thermal energy. These solar fluid heating systems vary in efficiency but typically must be carefully oriented towards the angle of the incoming solar rays in order to achieve an acceptable efficiency.

For systems heating water for use in a building, these systems are typically mounted to the roof of the building. This requires long fluid lines running from the roof to the building water systems, which are typically located in the basement or first floor of the building. They may require structural modifications to the roof to assure that the roof can accommodate the weight of the solar panels and associated hardware. Such systems therefore typically require professional installation and may take several days to complete. The initial labor and material costs associated with installing such systems on roofs and of providing the long plumbing lines to transport fluid to and from the panels has a considerable impact on the payback associated with switching from more conventional gas or electric water heating systems to using such solar water heating systems.

For solar water heating systems used to heat a swimming pool, the solar panels may be mounted to a roof of a nearby pool house, thereby having the same disadvantages as those systems mounted to roofs of other buildings. Alternatively, the solar panels may placed on the ground, near the pool, detracting from the appearance of the pool and sometimes consuming a portion of the land adjacent the pool that may be used by people for entertainment purposes.

The fluid holding chambers of these solar panels may have an outer container formed of a transparent material, such as glass, and an inner chamber formed of a heat absorbing material, such as stainless steel, in which fluid is heated and stored. It is critical for efficiency that the inner chamber be effectively sealed from the outer chamber. It would be beneficial to provide a solar water heating system that is easy to manufacture and in particular provides a low cost and effective sealing of the inner chambers.

Today the direct-embedded type of solar water heaters is widely used because of their high transferring efficiency, rapid heat up and low cost. However, there are also many disadvantages, such as the less visually pleasing nature of the roof installation as well as safety issues. This type of solar water heater is generally restricted in high residential buildings.

The split wall-mounted solar water heaters that are commonly used in multi-story and high-rise apartments are structured into two parts, the solar collector and hot water storage tank. The former is mounted on the exterior wall in the balcony or wall, the latter is usually placed somewhere in the balcony or indoors. Usually metal pipes, such as copper pipes, are used for installation. A heat exchanger using pipelines from collectors and water storage tank, are used to heat up the water stored inside the tank. The split wall-mounted solar water heater provides a good solution to pressure, installation, antifreeze and other issues, but it has some critical issues such as low collection efficiency, slow heat up, and a comparatively low hot water temperature. In addition, it consumes extra indoor space for the tank installation.

BRIEF SUMMARY OF THE DISCLOSURE

The present disclosure provides a fluid storage unit that may be assembled into solar heating system having panels.

In particular, in one exemplary implementation, the fluid storage unit may include an elongated cylindrical hollow vessel having at least one opened end; an inwardly oriented annular sealant ridge located adjacent the open end of the vessel; a sealing ring proportioned to fit within the open end of the vessel and abut the ridge; and a cover having a bowl shaped portion proportioned to selectively fit within the open end of the vessel and abut the sealing ring and the inwardly oriented sealant recess; such that, upon compression of the bowl into the open end of the vessel, the bowl shaped portion of the cover compresses the sealing ring against the ridge forming a fluid tight seal between the cover and the vessel.

In other variations, the bowl may have a peripheral flange selectively formable to grip the open end of the vessel to thereby compress the bowl shaped portion of the cover into engagement with the sealing ring. The bowl and the vessel may be formed of stainless steel material and the sealing ring may be an O-ring formed of a resilient material. The vessel may be disposed within a generally transparent outer chamber to form a thermal energy collection system.

In another exemplary implementation, the vessel may have a second open end opposite the first open end, the second open end being selectively closed by a second cover. In this implementation, an annular sealant emboss located adjacent the second open end of the vessel may selectively cooperating with a base, a second sealing ring and the emboss to selectively seal the second end of the vessel.

In further variations, a spanner nut may be provided to selectively drive the base against the second sealing ring to form a seal between the second cover and the vessel. The base may be provided with an inlet and an outlet for fluid flow into and out of the vessel.

In yet another exemplary implementation, a modular solar thermal storage unit may have a generally transparent solar energy collection chamber, a hollow vessel fitted in the chamber, and a base closing open lower ends of the chamber and the vessel. A cover may be attached to an open upper end of the vessel compresses first sealing ring against a ridge adjacent the upper end of the vessel to form a fluid tight seal between the cover and the vessel. A base may be attached to an open lower end of the vessel and an open lower end of the chamber by a spanner nut compresses a second sealing ring against an emboss adjacent the lower end of the vessel to form a fluid tight seal between the base and the vessel. The base may also compress a thermal ring against the lower end of the chamber to form a thermal seal between the base and the chamber. The base may be provided with an inlet and an outlet for fluid flow into and out of the vessel.

In still another exemplary implementation, the present disclosure further provides a modular solar thermal storage unit and tankless solar water heater, having a stainless steel vessel formed of a tube with two opened ends; a sealant ridge located near its upper end; a stainless steel a bowl-shape cover adapted to close the upper end by trapping an o-ring between the cover and the ridge.

BRIEF DESCRIPTION OF THE DRAWINGS

Some configurations of the Tankless Water Heater will now be described, by way of example only and without disclaimer of other configurations, with reference to the accompanying drawings, in which:

FIG. 1 is a schematic front elevational view of an exemplary solar panel including a plurality of solar water heating components mounted to a frame.

FIG. 2 is a schematic front elevational view of two fluid storage units of the solar panel of FIG. 1 with the frame removed, the fluid storage units being shown connected in series.

FIG. 3 is an exploded view of front sectional view of an exemplary fluid storage unit of FIG. 2 showing a heat-absorbing chamber, a fluid vessel, a cover, a base, two seal rings and a thermal seal.

FIG. 4 is a schematic front sectional view of a portion of an exemplary fluid storage unit of FIG. 2.

FIG. 5 is a partial enlarged sectional view of portion of FIG. 4 indicated by circle 5.

FIG. 6 is a partial enlarged sectional view of portion of FIG. 4 indicated by circle 6.

DETAILED DESCRIPTION OF THE DRAWINGS

The drawings generally relate to a new type of tankless solar water heater that is assembled from plurality solar thermal energy storage units. Key structures include a hollow stainless steel vessel, an annular abutment located adjacent the top of the vessel, a stainless steel bowl-shape cover, which cooperates with a sealant ring to close the top of the vessel. The bottom of the vessel can be inserted into base having an inlet and an outlet for water flow. The stainless steel vessel has an annular emboss located adjacent bottom of the vessel, which cooperates with a sealant ring and the base to close the bottom of the vessel. A spanner nut fastens the vessel to the base. The evacuated solar collectors are slid over the stainless steel vessels. A thermal washer is installed on the surface structure of the modular base. The lower edge of the collector engages the thermal washer to provide insulation for the collector. The base has water inlet and outlet port that are connected with external pipelines for input and output of water flow. The water outlet is close to the modular base; while, the water inlet is remote from the modular base.

The solar thermal energy storage units have 30% higher absorbing efficiency in comparison with other split wall-mounted solar water heaters at identical sizes. This new solar water heater can be as a construction part, integrating with architecture, no extra indoor or balcony space is needed.

Referring now to the drawings, exemplary solar panels and fluid storage units and components are shown in detail. Although the drawings represent exemplary configurations, the drawings are not necessarily to scale and certain features may be exaggerated to provide a better illustration and explanation of a configuration. The configurations set forth herein are not intended to be exhaustive or to otherwise limit the device to the precise forms disclosed in the following detailed description.

Referring to FIG. 1, an exemplary solar panel 10 is illustrated consisting of a frame 12 supporting a plurality of tankless solar collector units or fluid storage units 20. The frame may consist of a top frame member 14, a bottom frame member 16 and two side frame member 18. While five fluid storage units 20 are illustrated, the number of fluid storage units 20 used in any solar panel 10 will depend on the dimensions of available or optimal solar heat collecting components and the desired proportions of solar panel 10. The solar panel 10 includes a fluid inlet 22 and a fluid outlet 24 communicating fluid to and from the fluid storage units 20.

As shown generally in FIGS. 2-4, but best shown in FIG. 2, a plurality of fluid storage units 20 may be connected in series. Each fluid storage unit 20 may consist of a glass housing 28 containing a metal tube 30, communicating with fluid inlet lines 32 and fluid outlet lines 34 incorporated into a base 36, each described later herein. The fluid inlet line 32 of a first fluid storage unit 20 communicates fluid with the fluid inlet 22 (see FIG. 1) of solar panel 10. The fluid outlet line 34 of the first fluid storage unit 20, and of each subsequent unit 20, communicates with the fluid inlet line 32 of the next adjacent fluid storage unit 20 to provide a series connection between the fluid storage units 20, as shown in FIG. 1. The fluid outlet line 34 of a final fluid storage unit 20 communicates with the fluid outlet 24 (see FIG. 1) of solar panel 10.

Referring now to FIGS. 3 and 4, details of an assembly of the fluid storage unit 20, a base 36 and associated components are shown. The system in FIG. 3 is shown in a preassembled exploded form and may comprise, in sequence, a first beveled flexible ring 40, a glass housing 28, a second beveled flexible ring 42, a rubber ring 44, a cap 46 having an internal thread, not shown, a metal washer 48, a metal dish 50, a first flexible o-ring 52, a metal tube 30 having an internal annular ridge 56 proportioned to abut the first flexible o-ring 52 and an external annular ridge 58 proportioned to abut a second flexible o-ring 60, a fluid outlet pipe 62, a deflector plate 64 and a base 36 having an external thread at 66 for mating with the internal thread of the cap 46. These various components, there assembly and function will be now be described.

The glass housing 28 may be formed of a suitably durable heat conducting glass and has suitable external and internal coatings to facilitate efficient absorption of solar energy and transfer of the solar energy in the form of heat to the interior of the housing. The glass housing 28 may be formed of two layers of clear glass with a vacuum therebetween, as shown in FIG. 4. A nipple 68 is formed at the top as a part of the vacuum process. An energy absorbing coating may be applied to the outer wall of the inner tube portion and a reflective coating may be applied to the inner wall of the glass housing 28. The metal dish 50 and the metal tube 30 may be formed of a stainless steel having suitable strength, heat transmissivity and other properties.

To assemble the system of components shown in FIG. 3 into the assembly shown in FIG. 4, the metal dish 50 must be sealed to one end of the metal tube 30, as best shown in FIG. 5 to close the top of the metal tube. This is done by inserting the metal dish 50 and the first flexible O-ring 52 into one end of the metal tube 30 until the metal dish 50 compresses the o-ring 52 against the internal annular ridge 58 to form a water tight seal between the metal dish and the tub, and then attaching the metal dish to the tube, such as by a weld 70. The metal dish may be bowl shaped, having a generally flat circular portion 72 and an annular flange portion 74 proportioned to facilitate suitable engagement with the o-ring 52. As shown, the metal dish 50 is affixed to the tube 30 by electro-welding while the remainder of the tube 50 is led by water. Alternatively, the metal dish 50 may be affixed to the tube 30 by brazing, coining, crimping, threaded engagement, crimping roll forming, drawing or other mechanisms, depending on the pressures and temperatures expected to be experienced by the assembly.

To further assemble the system of FIG. 3 into the assembly of FIG. 4, one end of fluid outlet pipe 62 is inserted into a bore 63 in the base 36 so as to communicate with fluid outlet line 34. The deflector plate 64 is mounted to the base 36, for example by a screw, not shown, and extends over a bore 65 in the base leading to the fluid inlet line 32 so as to deflect the incoming fluid to minimize the mixing of the colder inlet fluid with the heated fluid above. Second o-ring 60 is slid onto the lower end of the metal tube 30 until it abuts the external annular ridge 58 thereof and the metal tube 30 is rested on the top of the base 36. The metal washer 48 and the cap 46 are fitted over the metal tube 30 and lowered into threaded engagement with the base 36. As seen in FIG. 6, when the cap 46 is threaded onto the base 36, the o-ring 60 is compressed between the base 36 and the external annular ridge 58 while the metal washer 48 is trapped between the cap 46 and the external annular ridge 58, forming a watertight seal between the base, the cap and the tube.

To complete assembly, the glass housing 28 is fitted over the tube 30 and rests on the rubber ring 44 which in turn rest on the cap 46. Rubber ring 44 as a seal closing the annular gap between the glass housing 28 and the tube 30 to form a thermal seal that reduces the loss of heat from the glass housing 28. The first and second beveled flexible rings 40 and 42 are coupled respectively to the upper and lower frame members 14 and 16 of solar panel 10 to gently but securely hold the glass housing 28 in the proper position within frame assembly 12 (see FIG. 1). Flexible rings 40 and 42 may be formed of a low heat transmissible material to provide a thermal break between the frame assembly 12 and the glass housing 28.

Thus, the disclosure provides a modular solar thermal storage unit and tankless solar water heater, having a stainless steel vessel formed of the tube 30 closed at the top by a bowl shaped cover 50 and closed at the bottom by the cap 46 and base 36. The vessel has an inlet and an outlet, formed in the base 36, to permit cold water to flow into the vessel, be heated by the impinging solar rays, and then to flow out of the vessel for use. The outlet includes an outlet pipe 62 retrieving water from the upper portion of the vessel to deliver through the base 36 to the next adjacent vessel or to the outlet line 24.

It will be appreciated that, in comparison with existing products, the disclosed system of a modular solar thermal storage unit and a tankless solar water heater provide significant benefits. For example, this system uses tankless design and therefore no extra indoor space is needed. This system uses thermal containment design, so integrating the solar collection with the thermal storage, resulting in high efficiency. This system uses vertical installation, which is suitable to work well in all four seasons, in particular, to reach higher efficiency in winter. Therefore, this technology satisfies well the hot water demand for customers. This system is visually pleasing in architecture. This system can be used for radiant floor heat in a solar heat system. This system has more 30% higher absorbing efficiency in comparison with other split wall-mounted solar water heaters. This system is able to operate under pressure with stable temperature, and is suitable to more applications.

It will further be appreciated that, to solve the technical issues of existing solar water heater products, the illustrated solar panel 10 provides new solar heat storage units that can be assembled to what is called as a tankless solar water heater. In the structure, this new solar water heater not only integrates solar thermal collection with the heat storage together, but also delivers high efficiency in collection, quick heating-up, and other beneficial features. In addition, the stainless steel vessel is sealed with non-welded connection, operates under pressure, is safe and easy to be replaced in service, etc. This tankless solar water heater can be installed independently, and also can be used as a construction part. No extra space is needed in the balcony and indoor area.

It is to be understood that the above description is intended to be illustrative and not restrictive. Many configurations and applications other than the examples provided would be apparent to those of skill in the art upon reading the above description.

For example, it should be noted that exemplary solar panel 10 described herein may heat water or another working fluid. Water or other fluid circulated through solar panel 10 for heating may be ultimately used directly by a consumer, such as in a residential central water system or in a swimming pool, or may be used as the working fluid or a secondary fluid for collecting and storing heat which may then be transferred to the water or other fluid used directly by the consumer using an appropriate heat transfer system, (not shown). If water is used, for example, heated water may be directly delivered from solar panel 10 to the point of use, such as to a swimming pool.

It will be appreciated that heated water may be delivered from solar panel 10, if desired, be to an additional water storage tank, (not shown), for later use. If the water is delivered to a water storage tank, the tank may be a passive storage tank or may be a water heater tank having its own heating system to supplement the heating of the solar water heating system, for example, at a time when the demand for heated water exceeds the output of the solar water heating system. Alternatively, solar panel 10 may be used as a water storage tank itself, delivering heated water directly to the point of use when and if required and storing the water at other times. However, a significant advantage of the present system is that the solar panel may be used without any additional storage tank.

Features shown or described in association with one configuration may be added to or used alternatively in another configuration. The scope of the device should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the arts discussed herein, and that the disclosed systems and methods will be incorporated into such future configurations. In sum, it should be understood that the device is capable of modification and variation and is limited only by the following claims.

All terms are intended to be given their broadest reasonable constructions and their ordinary meanings as understood by those skilled in the art unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as “a” and “the,” should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary. 

1. A fluid storage unit comprising: an elongated cylindrical hollow vessel having at least one opened end; an inwardly oriented annular sealant ridge located adjacent the open end of the vessel; a sealing ring proportioned to fit within the open end of the vessel and abut the ridge; and a cover having a bowl shaped portion proportioned to selectively fit within the open end of the vessel and abut the sealing ring and the inwardly oriented sealant recess; such that, upon compression of the bowl into the open end of the vessel, the bowl shaped portion of the cover compresses the sealing ring against the ridge forming a fluid tight seal between the cover and the vessel.
 2. The storage unit of claim 1 wherein the bowl further comprises a peripheral flange selectively formable to grip the open end of the vessel to thereby compress the bowl shaped portion of the cover into engagement with the sealing ring.
 3. The storage unit of claim 1 wherein the cover is comprised of stainless steel material.
 4. The storage unit of claim 1 wherein the vessel is comprised of stainless steel material.
 5. The storage unit of claim 1 wherein the sealing ring comprises an O-ring formed of a resilient material.
 6. The storage unit of claim 1 wherein the vessel in disposed within a generally transparent outer chamber to form a thermal energy collection system.
 7. The storage unit of claim 1 wherein the vessel has a second open end opposite the first open end, the second open end being selectively closed by a second cover.
 8. The storage unit of claim 7 further comprising an annular sealant emboss adjacent the second open end of the vessel and a second sealing ring, said second cover selectively cooperating with the second sealing ring and the emboss to selectively seal the second end of the vessel.
 9. The storage unit of claim 8 further comprising a spanner nut engageable with the second cover to selectively drive the second cover against the second sealing ring to form a seal between the second cover and the vessel.
 10. A modular solar thermal storage unit comprising: a generally vertically disposed elongated cylindrical hollow vessel having an open upper end comprised of a heat conductive material; an inwardly oriented annular sealant ridge located adjacent the open upper end of the vessel; a sealing ring proportioned to fit within the open upper end of the vessel and abut the ridge; and a cover comprised of a heat conductive material and having a bowl shaped portion proportioned to selectively fit within the open upper end of the vessel and abut the sealing ring and the inwardly oriented sealant recess such that, upon compression of the bowl into the open end of the vessel, the bowl shaped portion of the cover compresses the sealing ring against the ridge forming a fluid tight seal between the cover and the vessel.
 11. The storage unit of claim 10 wherein the bowl further comprises a peripheral flange selectively formable to grip the open end of the vessel to thereby compress the bowl shaped portion of the cover into engagement with the sealing ring.
 12. The storage unit of claim 10 wherein the sealing ring comprises an O-ring.
 13. The storage unit of claim 10 further comprising a generally transparent solar energy collection chamber formed of a heat absorbing material, said vessel being proportioned for selective insertion into the chamber.
 14. The storage unit of claim 10 further comprising: an open lower end of the vessel; an annular sealant emboss located adjacent the lower upper end of the vessel; a second sealing ring proportioned to selectively abut the emboss; and a base proportioned to close the lower end of the vessel and abut the second sealing ring and compress the second sealing ring against the emboss to selectively form a fluid seal between the base and the vessel.
 15. The storage unit of claim 14 further comprising a spanner nut engageable with the base to selectively drive the base against the second sealing ring to form said seal between the base and the vessel.
 16. The storage unit of claim 14 wherein the base further comprises an inlet and an outlet for fluid flow into and out of the vessel.
 17. The storage unit of claim 14 further comprising: a generally transparent solar energy collection chamber formed of a heat absorbing material having an open lower end and a closed upper end, said chamber being proportioned for selective acceptance of the vessel through the lower end of the chamber; and a thermal washer disposed adjacent an upper surface of the base engageable with the lower end of the chamber selectively forming a thermal seal between the solar energy collection chamber and the base.
 18. The storage unit of claim 14 wherein the second sealing ring comprises an O-ring.
 19. The storage unit of claim 14 wherein the emboss extends outwardly from the vessel and the second sealing ring fits on the outside of the vessel.
 20. A modular solar thermal storage unit comprising: a generally transparent solar energy collection chamber formed of a heat absorbing material having an open lower end and a closed upper end, a generally vertically disposed elongated cylindrical hollow vessel having an open upper end and an open lower end, said vessel being disposed with said chamber; said vessel further having an inwardly oriented annular sealant ridge located adjacent the open upper end of the vessel and an outwardly oriented annular sealant emboss located adjacent the lower end of the vessel; a first sealing ring fitted within the open upper end of the vessel and abutting the ridge; a bowl shaped cover fitted within the open upper end of the vessel, said bowl having a peripheral flange formed to grip the open end of the vessel to thereby compress the cover into against the first sealing ring, thereby compressing the sealing ring against the ridge to forming a fluid tight seal between the cover and the vessel; a second sealing ring fitted outside of the open upper end of the vessel and abutting the emboss; a base having an inlet and an outlet for fluid flow into and out of the vessel, said base being disposed adjacent the lower ends of the chamber and the vessel and abutting the second sealing ring; a spanner nut engaging the base to drive the base against the second sealing ring to form said seal between the base and the vessel; and a thermal washer disposed adjacent an upper surface of the base engageable with the lower end of the chamber forming a thermal seal between the solar energy collection chamber and the base. 